The work presents data from nine Institute of Meteorology and Water Management (IMGW) stations collected from 1971 to 2005 in central-east Poland. The relative precipitation index (RPI) was applied to determine the frequency of individual drought classes during the growth period. Moreover, spatial distribution of precipitation amounts in the study area was presented. Also, the direction and significance of tendency for changes in precipitation were presented. In the study years, monthly precipitation amounts varied greatly during the growth period in central-east Poland. The lowest precipitation sums (335 mm) during the growth period (April-September) were recorded in the south-western part of the study area, whereas the highest precipitation sums (367 mm) were found in the north-eastern part of the area. The highest long-term (1971-2005) average precipitation amounts were recorded in July (74 mm) and June (72 mm), and the lowest ones in April (38 mm). Analysis of the frequency of individual drought classes according to the relative precipitation index showed that typical months were three and six times as frequent as extremely dry and wet months, respectively. Severe droughts occurred the most frequently in June and April; very dry and very wet spells were noted in April, and extremely wet periods in July. Analysis of the slopes of the regression line representing the rate of change in precipitation sums during the study period showed that the values of the slopes were close to zero and statistically insignificant. Statistically significant changes were recorded only in June in Białowieża, where the monthly precipitation amount decreased by 17.4 mm/10 years, and in August in Legionowo and Pułtusk, where the respective declines amounted to 13.5/10 years and 9.9 mm/10 years.

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